The city of Amsterdam wasn’t quite sure what to do with three abandoned sewage treatment silos, so they decided to hold a competition to determine the best adaptive reuse project. One of the projects submitted for the competition was by Amsterdam-based NL Architects, who proposed to transform the silos into an incredible set of climbing towers. In addition to the climbing areas both inside and outside the silos, the project would include multi-purpose areas, offices, restaurants and other commercial spaces.

Similar to the Denmark Water Tower Renovation the Silo Project as proposed by NL Architects involves taking two of the towers and extending their roofs up 18 meters to the maxium height the towers could support. Inside tower A is a 40 meter high climbing atrium that looks like an inverted funnel with various cantelivers, wall facets, and overhangs to challenge climbers. Below the climbing atrium is a cafe and bouldering room while above is a hotel and training facility. Tower B houses a rooftop restaurant, office space, a salon, music studio, and a movie theater. The two towers are connected via a footbridge at the original rooftop height of the silos.

The climbing tower bulges in a couple of spots to make the climbing area even more interesting and challenging. A number of routes are also accessible on the outside of the silo. Climbing silos are actually fairly common here in the US especially in the Midwest, like in downtown Oklahoma City at Rocktown, which is a former grain silo transformed into a 16 room climbing gym with 90 foot walls.

As cool as this idea is, unfortunately the NL Architects design was not chosen by the Amsterdam City Council. Instead, they chose a project designed by Arons en Gelauff, which will be called the Annie MG Schmidt House. While also a multi-purpose cultural center, the Annie MG Schmidt House was a bit more family oriented with a playground, more restaurants and shops. The new center is expected to be opened in 2011.